As the most fundamental wireless access technology, channel coding plays a key role in ensuring reliable transmission of data. In an existing wireless communications system, channel coding is usually performed by using a turbo code, a low-density parity-check (LDPC) code, and a polar code. The turbo code cannot support information transmission at an excessively low or excessively high bit rate. For medium/short packet transmission, due to encoding/decoding characteristics of the turbo code and the LDPC code, it is very difficult for the turbo code and the LDPC code to achieve ideal performance in a case of a limited code length. In terms of implementation, the turbo code and the LDPC code have relatively high computational complexity in an encoding/decoding implementation process. The polar code is a good code that has been theoretically proved to be able to achieve the Shannon capacity and has relatively low encoding/decoding complexity, and therefore is more widely applied.
However, with rapid evolution of wireless communications systems, future communications systems such as 5th generation (5G) communications systems will have some new characteristics. For example, three most typical communication scenarios include enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC). The communications scenarios have higher requirements on encoding/decoding performance of the polar code.
Reliability ordering for polarized channels plays a key role in the encoding/decoding performance of the polar code. However, at present, accuracy of reliability ordering for polarized channels is not desirable, hindering further improvement of the encoding/decoding performance of the polar code during application.